Method and apparatus for manufacturing air spring



J. l.. HoLLls 2,971,562

METHOD AND APPARATUS FOR MANUFACTURING AIR SPRING e sheets-sheet 1 Feb.14, 1961 Filed Feb. 1, 1957 ATTY.

INVENToR. v JACK .Ho1 L|s l I l I l l I l l l l|...VI f l l.: l.: l.: NSQQ hllllw A N. J2 .Il IIIIIIIIIIMIMII ET. E wfff :Il I l l I IIL" G bwms wh .ws Ns \v\ \\m$ RNA, %-v\ wem,\\ .II| .|.1 |Il.l.|| NN, QN\ Nw \NQN\ Y \\J n |.lll l l l Holl la llmml Smm IGMNW R n@ QN NN MN MN emm\SSR Feb. 14, 1961 J. L. HoLLls 2,971,562

METHOD AND APPARATUS FOR MANUFACTURING AIR SPRING Filed Feb. 1, 195? esheets-sheet 2 a a/ 23 24 j /zda /za FIC-3.4

FIGS

INVENTOR. JACK .HoLLls J@ 3/ ATTY.

Feb. 14, 1961 .1.1.. HoLLls 2,971,562

METHOD AND APPARATUS FOR MANUFACTURING AIR SPRING Filed Feb. l, 1957 6Sheets-Sheet 5 ein NVENTOR. ./219 JACK l.. HCl-Lis AT TY.

Feb. 14, 1961 J. L. HoLLls 2,971,562

METHOD AND APPARATUS PoR MANUFACTURING AIR SPRING Filed Feb. 1, 1957 esheets-sheet 4.

' FIG.9

INVENTOR. JACK L. HOLLIS ATTY.

Feb. 14, 1961 J, L HOLL, 2,971,562

METHOD AND APPARATUS FOR MANUFACTURING AIR SPRING Filed Feb. 1, 195'? 6Sheets-Sheet 5 VPM Q LL

INVENTOR. JACK L. HOLLIS AT TY.

Feb. 14, 1961 1 HQLLls 2,971,562

METHOD AND APPARATUS FOR MANUFACTURING AIR SPRING INVENToR. JACK HOLLISI: II

ATTY

United States Patent NIETHOD AND APPARATUS FOR MANUF AC- TURING AIRSPRING Jack L. Hollis, Cuyahoga Falls, Ohio, assignor to The FirestoneTire & Rubber Company, Akron, Ohio, a corporation of Ohio Filed Feb. 1,1957, Ser. No. 637,793 19 Claims. (Cl. 154-1) This application relatesto air springs and more particularly to improved methods and apparatusfor manufacturing air springs.

An air spring which has had an outstanding commen cial success in busand truck wheel suspensions consists of a two-convolution body ofrubberized fabric plies, the ends of which are wrapped about andanchored to inextensible rings to form beads at the ends of the airsprings. Such air springs are designed to operate under air pressureswhich are usually in the range of about 70-80 pounds per square inch,but under some service conditions the pressures may be as high as1GO-150 pounds per square inch.

The air springs must have suflcient flexibility to undergo deflectionfor a great many cycles and must of course have sufficient mechanicalstrength to retain the high fluid pressures to which they are subjected.These twoV requirements of liexibility and of mechanicalstrength can beachieved to the fullest extent only by favorable methods of manufacturesuch as those embodying the present invention.

According to the present invention, an air spring having theseproperties is manufactured by assembling plies of essentially weftless,rubberized fabric in the form of a cylindrical body on a building drum.The plies at each end of the air spring are then expanded outwardly tolarger diameters so that they can -i'irst engage and then be wrappedabout and anchored to their respective bead rings. The expansion isperformed by circumferentially spaced members in the building drum whichforce thel plies radially outwardly into wedging engagement with thebead rings which are held in p'ace for this purpose by chucking meanswhich hold the bead rings externally during this operation. When theplies are expanded, the supportl of the bead rings is transferred fromthe chucking means to the expanded plies which support the rings attheir inside surfaces and while the ead rings are so held, the endportions 'of the plies are turned about the rings to form the beads. Thearrangement is advantageous from the standpoint of convenience andeconomy of manufacture and it enables an air spring of a uniformly highquality to be produced.

Accordingly, it is a general object of the invention to provide animproved apparatus and method for manufacturing air springs.

A more specic object is to provide a building drum construction enablingthe fabric plies of an air spring to be expanded radially outwardly in amanner to engage and hold a bead ring against dislodgment when the pliesare subsequently turned and stitched about the bead ring.

Another object is Vto provide apparatus for expanding the fabric pliesof a cylindrical air spring body into outwardly flared form.

Yet another object is to provide a method of building an air springwhich consists in first assembling the body plies in cylindrical formand then expanding the plies at opposite ends to form a body of ilaringform terminating in beads of larger diameter than the cylindrical form.

Yet another object is to provide effective means to hold the beads of anair spring in place while the plies are expanded outwardly into contactwith the rings;

2,971,562 Patented Feb. 174, 19x61 Another object is to provide improvedmeans for turning the fabric plies of an air spring about bead rings t0form compact and storing bead structures.

Another object is to provide apparatus for building an air spring inwhich the building steps are performed virtually automatically and witha minimum of labor.

Another object is to provide a method of building an air spring whichwill be of uniformly high quality, which will be effective in operationand durable in service.

Further objects are to provide an apparatus for manui factoring airsprings which is simple and effective in design, which is rugged inservice and which requires a minimum of maintenance.

These and further objects and advantages will more fully appear from thefollowing description of a pre; ferred form of the invention, referencebeing had to the accompanying drawings in which:

Figure l is a side elevation of an air spring building drum andassociated apparatus embodying the present invention; v

Fig. 2 is a somewhat diagrammatic view showing in side elevation theessential parts of the apparatus of Figure l, the drum being shown justprior to the beginning of the building operations, with the bead holdingchucks in their loading position;

Figure 3 is a View similar to Figure 2 showing the bead holding chucksretracted and the plies of the air spring body assembled on the buildingdrum;

Figure 4 is a View similar to Figure`3 showing the bead holding chuckswhich at this time hold the bead rings, moved into position to positionthe beads for the ply expanding operation;

Figure 5 is a View similar to Figure 4 showing the next step in whichthe plies are expanded outwardly into contact with the bead rings; i

Figure 6 is a fragmentary View similar to Figure V5, but on a largerscale, showing the next step in the operation, with the bead holdingchuck withdrawn and indicating the manner in which the end portions ofthe ex'- panded plies are turned axially around the bead rings;

Figure 7 is a. view similar to Figure 6 showing the radial stitching ofthe inturned plies to complete the forming of the beads of the airspring;

Figure 8 is a View, partly broken away, of an air spring bodymanufactured in accordance with the present invention, the air springbeing shown just after it is removed from the building drum prior to theiinal shaping and vulcanizing operation; Y

Figure 9 is a side elevation, partly in section, of a finished airspring molded from an air spring body such as that shown in Figure S;

Figure l0 is a side view of the right-hand portions of Vthe buildingdrum or" Figure l, the view being on an clearly the details ofconstruction;

Figure 1l is a longitudinal sectional view of the apparatus of Figurel0, the View being taken in the plane indicated by the lines 11-11 ofFigure l0;

Figure 12 is a fragmentary view partly in longitudinal section of theright-hand portion of the building drum of Figure l0 and on a slightlylarger scale than Figure l0, showing the drum expanded and the pliesforced against the bead ring which is held in position by the beadchuck; -v

Figure 13 is a lfragmentary view similar to Figure l2 showing the pliesturned axially around the bead rings, the plies being broken away toshow the operation more Y clearly;

Figure 15 is a .sectional view similar to Figure 14 but showing thebuilding drum in the expanded position Wlth the plies in place on theexpanded drum;

Figure 16 is a right-end elevation'partially inV section of theright-hand bead holding chuck showing the manner in which it issupported and moved;

.Figure 17 is a side elevation of the bead holding chuck ofFigure 16 ona larger scale than Figure 16;

Figure 18 is anend elevation of the bead holding chuck. of Figure 17showing the manner in which the bead holding chuck engages and holds abead ring.

The apparatus and method of the present invention is illustrated andwill be described with reference to the building of a more or lessconventional twoconvolution air spring, referred to generally at in thedrawings, and which is of the type shown and described in detail in U.S.Patent No. 2,713,498 to Roy W. Brown, issued July 19, 1955, see Figure9.

f Such an air spring is initially built upon a drum in the form of asubstantially cylindrical body such as shown in Figure 8 and is laterexpanded and shaped by uid pressure into a heated mold and vulcanized inits flnal shape.

. Such an air spring 113 comprises a body of two plies 11 and 12 ofrubberized fabric, preferably nylon, the plies being initially bias-cutso that the cords extend at an angle of about 1518 to the longitudinalaxis of the air spring with the cords of one ply extending at an angleopposite to the cords of the other ply. The body plies are wrapped aboutand anchored to a pair of substantially circular bead rings 13 and 14 toform the beads 15 and 16 of the air spring. Usually the air spring hasan impervious lining 18 of neoprene rubber to enable it to hold airunder the required operating pressures.

It will be noted, from Figure 9, that the central portion 19 connectingthe convolutions of the air spring has a diameter smaller than thediameters of the beads 15 and 16. In the present example, it is thediameter of portion 19, which is the minimum'diameter of the nished airspring, which determines the diameter of the building drum, for while itis possible to expand portions of an uncured air spring to largerdiameters, it is not feasible to `shrink a portion to a smallerdiameter. Accordingly, the uncured air spring should have a body ofgenerally cylindrical form and of a diameter equal to the smallestdiameter of the tinished air spring and hence in the present example thebody plies must are outwardly at the ends to accommodate the largerdiameter beads.

Before describing inA detail the construction of the apparatus whichwill produce such an air spring body, it is believed that a generaloutline of the operation and function of the apparatus will be helpful.reference will lirst be made to Figure 1 and to the diagrammaticsketches of Figures 2 to 7, inclusive, in which only the major parts ofthe apparatus and the functional relation to each other are illustrated.In this initial disc ussion no eiort will be made todescribe the detailsof construction.

As shown in Figure 1 such apparatus comprises a building drum 20 whichis separable at about its midpoint into a pair of drum sectons 21 and22; the lefthand drum section .21 being mounted on a driven canti- Ylever shaft 23,-and the right-hand drum section 22 being mounted foridling rotation on a shaft 24. The outer ends 2S and 26 of the drum areprovided with recessed portions helping to form bead seats when the drumis expanded, the bead seats being Vadapted to receive and hold the beadrings 13 and 14 of the air spring during the latter phases of thebuilding operation. The drum ends 25 and 26 are radially expandable bymeans of a pair of tapered expanding mandrels 31 and 32. Finally, a pairof bead ring chucks 33 and 34 are provided to hold the `bead ringsinitially and to transfer them to the bead seats 27am 2s in the building0peration.

In the rst building step, `see YFigure 2, the drum sec- Accordinglytions 21 .and 22 are separated and the bead ring chucks 33 and 34 arepositioned in the gap between the drum sections so that the bead ringscan be loaded into the chucks. These bead ring chucks are open at oneside so that the inextensible wire bead rings 13 and 14 can be readilyinserted.

In the next step, see Figure 3', the drum section-s are broughttogether,and the bead ring chucks 33 and 34, carrying the bead rings 13 and 14,are moved outwardly beyond the ends of the drum to give the operatorfree access to the drum. The rubber .inner lining ply 18 is then appliedto the drum with the ejnds of the liner just overlapping the bead seats27 and 23. Then, the fabric plies 11 and 12 of bias-cut fabric, areapplied over the inner liner and the plies are. stitched together toform the body of the air spring. The fabric plies overlap the bead seatsand the inner lining by about one inch on each end.

In the next step, see Figure 4, the bead ring chucks 33 and 34 arebrought into position over the ends 25 and 26 of the drum so that thebead rings 13 and 14 are aligned with the bead seats 27 and 2S,respectively. The expanding mandrels 31 and 32 are then brought inwardlyinto contact with the ends25 and 25 of the drum thereby expanding theends of the drum radially outwardly and causing the grooved portionswhich comprise the bead seats 27 and 28 to move outwardly to grip thebead rings 13 and 14, see Figure 5. As soon as the bead rings are fullyseated in the bead Seats, the bead setting chucks 33 and 34 are expandedto release their grip on the bead rings and the chucks are moved axiallyaway from the working area of the'drum.

In the next step, see Figure 6, a pairof ply-turning sleeves 35 and 36are moved axially inwardly in a teled scoping movement over the expandedends of the drum to engage the ends of the plies 11 and 12 and turn themaround the bead rings 13 and 14 and back onto the body of the airspring.

The inwardly turned ply ends are then stitched firmly about the beads bymeans of a hand stitcher 150, or if desirable, by a powered contourstitcher. Prior to this stitching operation the ply turn-up sleeves 35and 35 are retracted so that they will not interfere with the stitchingoperation. An outer cover of gum rubber may be applied to the body ofthe air spring with this last ply of rubber overlapping the inturned plyends. During this last step the drum ends 25 and 26 remain expanded.

In order to remove theassembled air spring from the building drum, thedrum ends are collapsed by retracting the expanding mandrels 31 and 32and air under pressure is introduced between the drum section 21 and thebody of the air spring as the drum sections are separated. Thecompressed air releases the frictional grip of the body upon the drumsection 21 and as the sections move apart, the air spring is carried tothe right by the drum section 22. Air is then introduced between the airspring and the drum section 22 and the air spring is manually removedfrom the drum. The gap between the drum sections when they are fullyseparated is such `as to enable this stripping operation to be doneconveniently.

With this general outline ofthe function and operation `of theapparatus, the construction of the apparatus will now be described;first, in its general organization, and then in its details.

'Construction of the apparatus in general The manner in which the majorelements of the a;- paratus are assembled into an integrated machine isbest shown in Figure l. The shaft 23, which carries drum section 21 isjournalled in spaced bearings 41 and d?. and is drivenby conventionalmeans including the chain and sprocket arrangement 43, all of which issupported on a base 44 and enclosed by a housing 45. The shaft 24 whichcarries drum section 22 is journalled in suitable bearings 46, seeFigures 1'ad`l0, whicha're supported Vdetail in Figure l1.

surface comprises the building surface of the drum.

agr-ases '0 by a column 48 mounted on a carriage 49. The carriage .49fismovable in the longitudinal direction to carry the ldrum section 22bodily into and out of engagement with drum section 21, the carriagebeing driven by a longstroke pneumatic cylinder 51 whose piston rod 52is connected directly to the carriage. The carriage is guided in thismovement by a pair of parallel base members 53 which slide along fixedways 54 at the base 44 of the apparatus.

The bead ring chucks 33 and 34 are supported on carriages 56 and 57which are likewise movable in a longitudinal direction so that they canbe moved into and out of their operative positions. Each carriage issupported by and movable along a longitudinal extending threaded shaft58 and along a rectangular bar 59 parallel to the shaft 55. Both theshaft and bar are supported at their ends by the upright members 60 and61. The shaft 58 is provided with threaded portions 62 and 63 of rightand left-hand threads, respectively, and the carriages have internallythreaded sleeves 64 and 65 engaging the threaded portions 62 and 63 sothat rotation of the shaft 58 in vone direction will cause the carriagesand bead ring chucks to move closer together while rotation in theopposite direction will cause bead ring chucks to move apart, asdesired, in the building operation. The threaded shaft 58 may be rotatedby any suitable means. The

`carriages 56 and 57 have channel members 66 forming part of their baseswhich engage and slide along the rectangular bar 59, seeFigure 16.

The drum sections and the ply-expanding mechanisms In most respects thedrum sections 21 and 22 and the associated ply-expanding mechanisms arevirtually identical and accordingly only the right-hand drum sectionwill be described in detail. Where possible, the same reference numeralswill be applied to corresponding parts of both drum sections with theparts of the left-hand section 21 and associated apparatus beingidentified by the sufx a appearing after such reference numeral.

The construction of the drum section 22 is shown in Essentially, itcomprises a hub member 7l) which is keyed at 71 to the idling shaft 24.The hub supports the cylindrical shell 72 whose outer ln order to lockthe drum sections 21 and 22 together so that they will rotate as a unit,the drum section 22 is provided with a pilot portion 73 which is securedas by machine screws 74 to the hub 70 of the drum section. The pilotpo-rtion 73 is circular in section and has a plurality of splines 75which are adapted to engage in a splined recess 77 of the drum section21.

As mentioned above, the outer` ends of the drum sections are expanded toforce the plies outwardly and grip the beads of the air spring duringthe building operation. While a variety ofconstructions may be used,that illustrated in Figures l and ll is preferred. Thus thee drumsection 22 is slotted about its periphery as indicated at 79 to receivea series of pivotal segments 80. Each of the segments S0 fits closelywithin its slot so that its outer surface 81 lies iiush with thecylindrical surface of the drum, enabling the fabric plies to be laideasily upon the drum and to be stitched rmly together to form acylindrical air spring body, as described above. It will be noted thatthe extreme outer portions 82 of the slots 79 are not filled by thesegments but this is not objectionable, as this portion of the drumsupports the ply portions'which are to be turned about the bead ring andthe stitching which is done on these portions after the ply-turningoperation is suicient to unite the plies.

The segments 80 are shown in Figure 10 in retracted position. Theexpanded position of the segments is shown in Figures l2 and 13. Eachsegment 86 comprises a block of metal about one-half inch thick andhaving a shape best shown in Figures l2 and 14. Each .1 at side 83 ofthe segment has an arcuate slot 85 milled into it to a depth of 1A inchand opening as indicated at 86 to the inner end of the segment as shown.A

The segments, preferably 8 in number, are assembled with a spider-likemember, indicated generally at 87, comprising an annular ring'SS whichis secured to the hub 70 of the drum section 22 as by machine screws 89.A plurality of bracket members 91) Which are-circumferentially spacedabout and secured to the outside surface of the ring, are adapted toreceive and hold the segments for their pivoting movement. Each bracketmember 90 is U-shaped with parallel arms 91 extending outwardly from thebase of the bracket to define anotch 92 and each arm has an arcuate rib93 integral therewith extending out into the notch 92 about 1A inch. Thesegments 80 are assembled with the brackets 90 by fitting the inner ends of the segments between the arms 91 of the brackets with the ends ofthe ribs 93 entering the open ends 86 of the arcuate slots 85 in thesegments. The segments are then moved fully into the brackets by givinga slight clockwise rotary motion to the parts as they are forcedtogether. The brackets are of course positioned Within the drum section22 so that the notches 92 are radially aligned with the slots 79.

The segments are expanded radially outwardly as previously describedwith reference to Figure l1 and as shown more clearly in Figures l2 and13, by the conical nose 11H1 of the expanding mandrel 31 which is movedaxially inwardly into contact with the cam surfaces 96 of the segments.As the nose moves in under the segments, the segments are caused torotate upon the arcuate ribs 93 until they take the position shown inFigures l2 and 15. At the end of the forward movement of the mandrel 31,the end face 162 of the nose of the mandrel will labut the ring member87 and the nose of the mandrel will lie within and will support thesegments in their expanded position. ,The rotation of the segments takesplace about the centers of curvature of the arcuate ribs 93 of the slots85 which are designed so that the centers of curvature fall at'thesurface of the drum. This feature enables the fabric plies to beexpanded without imposing any longitudinal stress upon the plies andminimizes the wrinkling which would otherwise take place.

The expanding mandrel 31 is designed so that it not only rotates thesegments outwardly but also intermeshes with the expanded segments sothat the mandrel and segments as assembled together present a virtuallyunbroken surface to facilitate the stitching of the plies about the beadring. This is accomplished'by a plurality of ngers 103 which are securedto the body of the mandrel by radial anges 10S which are fastened bymachine screws 1616 to the radial iiange 167 of the mandrel. The fingers193 have tapered end surfaces 164i which are aligned with the surfaces81 of the expanded segments to forma continuous support surface for theplies. The fingers also have circumferential grooves which are alignedwith the grooves 99 of the segments to form the continuous unbroken beadseat 28. See particularly Figures 10 and ll.

The body of the expanding mandrel 31 comprises a long sleeve 112 whichhas a close sliding t upon the shaft 24, and the sleeve is keyed to theshaft by means of Va key (not shown) and a longitudinally extendedkeyway 113 in shaft 24, see Figure 1l. This arrangement permits themandrel to rotate with the shaft 24 and drum section 22 and yet have therequired longitudinal movement along the shaft With respect to the drumsection 22 when it is necessary to expand the segments. The mandrel ismoved along the shaft 24 by a pair of air cylinders 114 and 115 sectionsare brought together at the beginning Yof the As mentioned above, thebead ring 14 is held in a bead ring chuck 34 in such a relation to theexpanding drum segments that the bead ring 14 will seat and be heldwithin the bead seat 28 when the segments are fully expanded. Since thebead ring chucks 33 and 34 are identical in construction and operation,only the chuck 34 will be described. n

`Essentially the chuck 34 comprises a plurality of radially movable jawswhich take the form of grooved rollers 120 arranged in the form of acircle as shown in Figures 16 and 18. The rollers are journalledon-axially extending pins 121 which are supported by a pair of xedannular members 122 and 123 held together by machine screws 118 to formthe body of the chuck and mounted in fixed position to the carriage 57.Each pin 121 extends through aligned radial slots 124 in the members andare held to the members by the abutment of a radial ange 12S with member122 and by the abutment of a nut 126 at the end of the pin with member123. See Figure 12.

The grooved rollers 126 are moved from a circular position of smalldiameter (their closed position) in which they grip and hold the beadring 14 to a position of larger diameter (their open position) torelease the bead ring 14 by the arrangement best shown in Figures 12 and18. As shown in Figure 12, the annular members 122 and 123 are axiallyspaced to form a circumferential groove 127 in which a rotatable ringmember 125 is journalled. This ring member 123 has a plurality ofdiagonally extending slots 129 through which the pins 121 also extend.When the central ring member 128 is rotated with respect to the iixedmembers 122 and 123, the sides of the diagonal slots 129 act as cams toforce the pins radially back and forth in the slots 124 of the iixedmembers.

The relative rotation of the central ring 128 is produced by a pneumaticcylinder 130 which is pivotally mounted as indicated at 131 at its lowerend to a bracket 132 projecting radially from the upright column 133 ofthe chuck carriage 57 and is pivotally connected at 134 at its upper endto a boss 135 projecting radially from the central ring member 128, seeFigure 16. The pivotal connections 131 and 134 at each end of thecylinder enable the motion of the cylinderto be translated intorotational movement of the ring member 128.

At the beginning of the building operation the bead chuck 34 (and chuck33 as well) is positioned between the spaced drum sections, see Figure2, and the rollers 120 are in their open position so that the bead ring14 can be introduced into the chuck through a radially open chute 136with the bead ring coming to rest within the grooved edges of thelowermost rollers. The chuck is then closed (by rotation of the ringmember 12d) so that the bead ring 14 is gripped at its external surfacesand V.centered by the engagement of all of the rollers 1213.

The bead ring 14 is thus held securely against displacement until it issubsequently transferred to the expanded drum section 22. As soon as thebead rings are loaded in the chucks, the chucks are moved apart to theposition of Figure 3 to clear the drum for the building operation. Afterthe plies have been assembled on the drumthe chucks are moved intoposition, see Figures 4 and 5, where vthe bead rings are properlyaligned with respect to the segments 80 so that when the segments areexpanded the bead rings will be seated within the bead seats 27 and 2S,forcing the plies into the seats under them and oecoming partiallyembedded in the plies and sufficiently supported by the bead seats so asto be secure against displacement when the plies are later turned andstitched around the beads. The positioning the chucks is determined bystop members or any other suitable means for controlling the movement ofthe chuck carriages 56 and The ply-turning mechanisms After the ends ofthe fabric plies are expanded into conical shape by the expansion of thesegments, the portions of the plies projecting axially beyond the beadring 14,4 see Figure 12, are turned axially back and around the beadring 14 while it remains seated within the b'e'ad seat 2% by aply-turning sleeve 138 having a plurality of axial projections 139 orlingers corresponding in number and in size to the mandrel ngers 163which intermesh with the expanding segments S0. The inner surfaces ofthe sleeve proiections 139 lie in a circle which is slightly greater indiameter than the bead ring 14. When the sleeve 1.38 is moved inwardlytowards the drum section 22, the projections 139 move between the outerends of the segments and engage the fabric plies between the segmentsforcing the plies inwardly and about the bead ring in the manner shownin Figure 13.

As shown in Figure 10, the ply-turning sleeve 138 is mounted on asuitable hub member 14@ by means of the radial flanges 141 and 142 andthe screws 144 and the hub member 14d' is keyed as indicated at 145 tothe body 112 of the expanding mandrel 31 s'o that the ply-turning sleevewill rotate with the mandrel and with the drum section 22. By thisconstruction, it is ensured that the projections 139 will always meshwith the segments. The manner in which the ply-turning sleeve 138 iskeyed to the mandrel also permits the required longitudinal movement ofthe` sleeve upon the mandrel during the ply-turning operation, thislongitudinal movement being produced by a pair of pneumatic cylinders146 and 147 which act upon the py-turning sleeve through a yoke 148 anda bearing 149 similar to the bearing 117 of the expanding mandrel. Thearrangement thus permits the plyturning sleeve to turn with the shaft 24and at the same time enables longitudinal movement of the ply-turningsleeve on the mandrel.

After the plies have been turned axially around the bead ring, theply-turning sleeve 138 is withdrawn and the pies are stitched tightlyaround the bead ring by a stitcher which exerts radial stitchingpressure on the plies, see Figure 7, to compact the bead. Then the airspringv body is iinished and stripped from the building drum asdescribed above.

While the invention has been described in connection with thetwo-convolution bellows, shown and ,described in Figure 9, it can beused to advantage in the manufacture of two-convolution bellows having acentral portion of greater diameter than that of the beads such as theair spring shown and described Yin the co-pending US. patent applicationof Roy W. Brown, Serial No. 549,437, iiled November 28, 1955, and alsoin the production of a singe-convolution bellows such as that shown anddescribed in the copendng U.S. patent application of Roy W. Brown andlack L. Hollis, Serial No. 521,031, new abandoned, led July 1l, 1955,which is a singleconvolution air spring terminating in beads ofappreciably different diameter.

Various modifications and changes in the apparatus and method embodyingthe invention herein will no doubt occur to those skilled in the artWithout departing from the scope of invention the essential features ofwhich are summarized in the appended claims.

I claim:

1. For the manufacture of an air spring in which the air spring isformed in the shape of an initially cylindrical body of flexible,vulcanizable material, apparatus adapted to turn one end portion of saidbody radially outwardly and then axially inwardly about a substantiallyinextensible bead ring to form a beaded edge at said end, said apparatuscornprisinfy a substantially cylindrical drum providing internal supportfor said end portion, a plurality of circumferentially spaced segmentsinset in said drum and underlying said end portion, Asaid segmentshaving surfaces initially lying ush with the outersurfa'ce of said drumand said segments being rotatable, and an expanding mandrel movable withrespect to said segments to rotate said segments to swing them outwardlyin a radial direction to expand said end portion radially outwardly intoa flared form.

2. The apparatus of claim 1 in which said segments have inwardlydirected cam surfaces and in which said expanding mandrel has camsurfaces co-acting with the cam surfaces of said segments to swing saidsegments radially outwardly upon relative axial movement of saidexpanding mandrel with respect to said segments.

3. Apparatus according to claim 2, in which said expanding meanscomprises a conical surface movable within said segments to rotate themradially outwardly.

4. Apparatus according to claim l, in which said segments have straightcylindrical surfaces lying flush with said drum surface and haveinwardly directed rounded portions comprising cam portions co-actingwith said expanding mandrel, said segments being set within spacednotches in said drum surface.

5. Apparatus according to claim 4 and means hav- -ing arcuately-snapedribs on each side thereof projecting toward said segments and in whichsaid segments have arcuate grooves adapted to receive said ribs andsupport the segments thereon, the centers of curvature of said arcuateribs and grooves lying substantially at the surface of said cylindricaldrum.

6. The apparatus of claim l in which said segments havecircumferentially aligned notches to receive said bead ring in wedgingengagement when said segments are rotated outwardly into fully expandedposition.

7. The method of manufacturing an air spring which comprises forming acylindrical body of exible, vulcanizable material; expanding the endportions thereof in a radially outwardly direction and into wedgingengagement with a pair of inextensible bead rings, respectively, turningthe edges of said ared portions axially inwardly about said bead ringsand stitching said edges back into contact with said body and thereaftershaping and vulcanizing said body in the form of an air spring.

8. Apparatus for the manufacture of an air spring in which the airspring is formed in the shape of an initially cylindrical body offlexible, vulcanizable material, said apparatus being adapted to turnone end portion of said body radially outwardly and then axiallyinwardly about a substantially inextensible bead ring to form a beadededge at said end, means to hold said bead ring by the outer diameterthereof concentric with said end portion and axially inwardly of theextreme edge thereof, means to expand said edge portion radiallyoutwardly into wedging engagement with the inner diameter of said beadring and means to engage said end portion close to said bead ring and toturn the portion extending beyond said bead ring axially inwardly aroundsaid bead ring, and means to stitch said inturned material onto said airspring body adjacent said bead ring.

9. Apparatus for the manufacture of an air spring in which the airspring is initially formed in the shape of a cylindrical body offlexible, vulcanizable material, said apparatus including, incombination, means to hold a substantially inextensible bead ring by theouter surfaces thereof in a position adjacent one end of said air springbody and means to expand said one end of said body radially outwardlyinto frusto-conical form and into wedging engagement with the innersurfaces of said bead rrn lgO. The method of manufacturing an air springwhich comprises forming a cylindrical body of flexible, vulcanizablematerial, expanding said body at one end thereof into frusto-conicalform and turning the edge of said expanded portion about an inextensiblebead ring to form an inextensible beaded edge.

l1. Apparatus for manufacturing an air spring in which the air spring isinitially formed in the shape of a cylindrical body of exible,vulcanizable material, said apparatus comprising circumferentiallyspaced longitudinally extending segments providing internal support forsaid body, said segments being rotatable in a radially outward directionto expand one end of said air spring body into flaring form and meansmovable axially into said ared body to` intermesh with said segments andto provide, with said segments, substantially continuous internalsupport to said flared air spring body.

12. The apparatus of claim 1l in which s-aid segments are rotatabieabout their inner ends in a radially outward direction.

13. The apparatus of claim 1l and means movable axially to intermeshwith said segments, and to engage the edge portion of said ared airspring body and to turn said edge portion axially inwardly upon itselfand over said air spring body.

14. The apparatus of claim 13 in which said lastnamed means comprises atubular member having axially projecting fingers intermeshing with saidsegments and engaging said edge portion at the points between saidsegments.

15. Apparatus for manufacturing an air spring in which said air springis initially formed in a cylindrical body, said apparatus comprising acylindrical drum supported on a longitudinal shaft, segments at lthesurface of said drum and rotatable about their ends in a radiallyoutward direction to engage and expand one end of said cylindrical bodyinto flaring form and means mounted on said shaft for rotation with saiddrum and movable longitudinally along said shaft to engage said pivotalsegments and expand them outwardly.

16. Apparatus according to claim l5 and means mounted on said shaft andmovable longitudinally thereon to intermesh with said segments andengage the edge portions of said air spring body extending between saidsegments and turn said edge portion axially inwardly upon the adajcentair spring body.

17. Apparatus according to claim 15 in which said means comprises alongitudinally extended hub portion telescoping over and keyed to saidshaft for rotation therewith and longitudinal movement thereon.

18. Apparatus according to claim 17 in which said hub member has camsurfaces engaging said rotatable segments to expand them outwardly.

19. An apparatus according to claim 17 and additional means mounted onthe longitudinal extension of said hub member for rotation with said hubmember and slidably movable in an axial direction thereon and having aplurality of projections intermeshing with said pivotal segments toengage the portions of said air spring body expanding said rotatablesegments in their expanded position to turn the edge portion of said airspring body axially and back upon said body.

References Cited in the le of this patent UNTTED STATES PATENTS1,757,750 Stevens May 6, 1930 2,221,470 Brown Nov. 12, 1940 2,251,904Breth et al. Aug. 12, 1941 2,313,035 Breth Mar. 9, 1943 2,339,559Charnes Jan. 18, 1944 2,409,974 Breth et al. Oct. 22, 1946 2,455,038Breth Nov. 30, 1948 2,614,952 Kraft Oct. 21, 1952 2,669,281 Breth Feb.16, 1954 2,715,932 Frazier Aug. 23, 1955 2,715,933 Frazier Aug. 23, 19552,874,458 Smith Feb. 24, 1959 FOREIGN PATENTS 978,163 France Nov. 22,1950 OTHER REFERENCES Automotive Industries Air Springs (December 15,1957), pages 54-57.

